This invention relates to fluid cooled photovoltaic cells which can absorb large power densities of sunlight without appreciable temperature rise and consequent loss of efficiency.
Since sunlight is a dilute power source, 1 kilowatt/meter.sup.2, it is necessary to collect it over a large area if the power needs of a home or a community are to be met. Semiconducting devices are more expensive than solar collectors, on a unit area basis, so there is economic advantage in concentrating the sunlight before it impinges on a photovoltaic cell. Because the efficiency of the cell falls off at elevated temperatures, it is necessary to use either low concentration levels or efficient cooling methods. The prior art does not deal adequately with the cooling of devices, especially large area devices, which are receiving solar power at concentration levels near 10.sup.3.